Improvement in stone-polishing machines



FINN..

sToNE-PoLlsHING MACHINE.

No.172,6l7. patented Jan. z5, l'af.

NIETERS, PMOTUUTHOGRAPHER, WASHINGTON. D. C.

nn-men STATES PATENT Grrrcng JAMES FINN, or CAMBRIDGEPORT,MASSACHUSETTS.

IIMPROVEWIENT IN STONE-POLISHING MACHINES.

Specification forming part of Letters Patent No. 172,617. dated January25, 1876; application filed November 16, 1875.

To all whom it may concern:

Beit known that I, JAMES FINN, of Cambridgeport, of the county ofMiddlesex and State of Massachusetts, have invented a new and usefulMachine for Grinding or Polishing Surfaces; and I do hereby declare thesame to be fully described in the following specication a-nd representedin the accompanying drawings, of which- Figure 1 denotes a frontelevation, Fig. 2 a longitudinal section, and Fig. 3 a transversesection, of it.

In such drawings, A denotes what I term the grinder-head shaft,77 whichstands vert'ically within a frame, B, is arranged in a suitable bearing,c, and extends through and is provided with a driving-gear, l),connected with such shaft by a projection, c, extending from said gearinto a groove, w, made lengthwise in the shaft. This shaft is to becapable of sliding vertically in its bearings. It has affixed to itslower end a head or disk, c, beneath which there is a cross, d, forreceiving and supporting the polishing-stones or grinders wedged to itsarms. This cross is held to the disk c by a series of screw-bolts, all,extending from it up through the disk, and held thereto by nuts cscrewed on such bolts, there being a helical spring, f, on that part ofeach bolt which is between the cross and the disk, all beingas'represented. lEncompassing the shaft is a tunnel or conical vessel,g, from'the lower part of which a passage, h, leads into the Shaft, anddownward to its lower end, there being a hole, x, through the cross atits center. A pipe, t', iixed to the frame B, extends out or directlyover the mouth of the tunnel, such pipe being to lead water frolna tankinto the tunnel. For thevpurpose of determining the amount of flowage ofthe water from the pipe, as well as to arrest it altogether, ascircumstances may require, such pipe may be provided with a stop-cock. Asmall circular ring or collar, l, grooved around its pe` riphery, andencircling and fixed to the shaft, receives in the groove the furcatedend of a lever, o. Two helical springs, m n, encompass the shaft, withthe aforesaid collar against and directly between them. The upper ofthese springs, at its upper end, rests against the upper bearing a,while the lower spring rests, at

its foot, on the driving-gear b, which engages with another such gear,1, iixed on a drivingshaft e, arranged as shown, and provided with onefast and one loose pulley. The said lever o is pivoted to an arm, p,extended down from the frame B, and has to its longer arm a hookedhandle or pendant, q, to catch into a toothed rack, r, fixed to theframe, and arranged as shown. The lever o, the lowerinost spring n, thehooked pendant g, and the rack r' constitute a presser, or means of'pressing the shaft A downward, in order to force and maintain thegrinders or polishers in contact with the slab of marble or article tobe reduced, such slab or article being placed and fixed, if necessary,on a movable platform, (l, arranged under the shaft, provided withparallel tongues a a', resting in grooved parallel guideways or rails ss, projecting upward from a carriage, D, that, in turn, has paralleltongues b b', that rest on lother and parallel grooved guide-rails t t,supported by a stand, E, and arranged at right angles to the rails s s.The stand E rests on the door F, upon which is ilxed one of two pivotalracks, G H, to receive the ends of two levers, I K. The other of thesaid racks projects from the carriage D. One of the levers works in ahorizontal plane and the other in a. vertical one," and one lever isconnected with the platform C by an arm, a', extended therefrom, thelever going loosely through the arm, and being held in place by pins c cgoing through it. The other lever is connected to the carriage D by aconnecting-rod, d2, hinged to both lever and carriage D, all being asshown.

The slab or slabs to be ground or polished being secured upon theplatform C, and grinding-stones or polishers being fixed to the arms ofthe cross d, and the shaft A being put in revolution, an attendant, bymeans of the presser, should depress the shaft, so as to force thegrinders or polishers down upon, and

hold them in contact with, the surface to be.

reduced. This having been done, he next is to seize hold of the leverswith his hands, and move, from time to time, the said levers, so asbring the entire upper surface of the Slab or stone under the action ofthe grinders or polishers, he in the meantime movlng the levers along intheir racks, as may be necessary, to

`enable him to advance the slab either endwise' or lengthwise. The Watersupplied to the tuunel will run into and down through the shaft,

and be discharged upon the cross and the slab.

The levers and their pivotal racks enable an attendant to impart to theslab or itsvoarriage motionsin directions at rightangles to each other,or others which are the result-ants of such motions at right angles, andthereby to move the slab along under the grinders, so as gradually tobring its entire surface under their operation.

The springs against which the cross rests enable the grinders to readilyadapt themselves to the surface to be dressed.

In the above-described machine, I claim as my invention as f'1loWs,viz':' Y

l. The combination of the racks G H and levers I K with the platform Cand its supporting-carriage D, provided with sustainingways, arranged asspecified.

2. The grinderlhead shaft A, provided with the tunnel g and the@duction-passage h, arranged With said shaft in manner and to operatewith the stationary pipe z', as set forth.

JAM-ES FINN. Witnesses:

R. H. EDDY, J. R. SNOW.

